Weapon-mountable optical sights and especially laser sights are becoming more commonly used on firearms, including handguns, long guns, and automatic weapons, air guns including air pistols and air rifles, airsoft guns, and various other types of equipment. Lasers emit a beam of coherent light that is concentrated and unidirectional, and therefore preferred for targeting use over other forms of light that are incoherent, relatively weak, and omni-directional.
In most cases, a laser sight is mounted to a scope to emit a laser light beam parallel to the axes of the scope and barrel from which a projectile is fired. The laser light appears as a small spot over long distances, enabling the user to place the spot on a target viewed through the reticle of the scope and, in doing so, indicate the trajectory of the projectile. In this sense, the laser sight is commonly described as a “laser designator.”
Whereas most laser sights use a red laser diode, infrared diodes and other laser light colors have been used, including green laser diodes. Green laser light beams, for example DPSS (diode-pumped solid-state) lasers, emit a laser light beam having a wavelength of 532 nm, which is advantageous because green light is at the peak of the human eye's sensitivity, thereby producing more visible light with less energy compared to other light sources. Such efficiencies reduce the power requirements of the laser, and therefore increase battery life. A commercial example of a laser designator using this technology is the ND-3® and ND-5® series available from Laser Genetics, Inc. In addition to generating a small diameter laser light beam for use as a laser designator, these products incorporate an optical collimator that enables the beam diameter to be increased to illuminate a much larger area. In this sense, the laser sight can also be described as providing a “laser illuminator” capability. The term “laser designator/illuminator” will be used herein to refer to laser technologies that provide a laser designator and/or laser illuminator capability.
Various other weapon-mountable optical sights have been proposed, for example, as represented in U.S. Published Patent Application Nos. 2011/0314720, 2011/0167708, 2011/0167707 and 2011/0047850. For example, 2011/0314720 discloses a laser sighting device that includes an ocular lens, a laser locator, and an illuminator unit adapted to be mounted on a weapon, 2011/0167707 discloses a tactical illuminator having a foregrip, power source, aiming laser, and illuminator, and 2011/0047850 discloses a weapon-mountable foregrip assembly that includes a built-in aiming laser and power source. However, still greater versatility would be desirable, particularly for weapons that may be used in multiple different tactical missions.